Rear Progressive Leaf Spring Kit 2010-13 RAM 2500/3500 Gas 1 Lift Carli SuspensionWhether you're using your vehicle as a daily driver or for weekend adventures, these progressive rate spring packs are designed to deliver optimal comfort and functionality while maintaining Light 3 4 ton cargo tow capacity. Features and Benefits: These full length progressive rate spring packs, custom built by Deaver Spring exclusively for Carli Suspension, are engineered with a two stage design, aiming to maintain a Light 3 4 ton cargo weight